Oregon Revised Statutes Revenue and Taxation § 305.418

(1) Transmitted through the United States mail, shall be deemed filed (a) on the date shown by the post-office cancellation mark stamped upon the envelope containing it, or (b) on the date it was mailed if there is also mailed to the tax court a declaration of mailing, signed by the appealing party or the attorney of the appealing party and verified by oath or affirmation, subject to penalties for false swearing, in substantially the following form:

I hereby declare under the penalties for false swearing contained in ORS chapter 162 that on the __________ day of __________, 2__, I deposited a complaint entitled __________, and dated __________, in a sealed envelope, with postage prepaid, in the United States Post Office at __________, Oregon (or other state of mailing), addressed to the Oregon Tax Court, 1163 State Street, Salem, Oregon 97301-2563 (or current address).

(2) Lost in transmission through the United States mail, shall be deemed filed on the date it was mailed if the appealing party: